mysql - MySQL对最后一个排序和分组

你好，我需要有关MYSQL查询的帮助
我有桌子

id | tn   | title    | customer_id |create_time | comment              |
1  | 1342 | sample1  | customer1   | 2012-01-01 | hello world          |
2  | 1342 | sample1  | customer1   | 2012-01-02 | hello world          |
3  | 1342 | sample1  | customer1   | 2012-01-03 | hello new world      |
4  | 3362 | sample2  | customer1   | 2012-01-02 | good bye world       |
5  | 3362 | sample2  | customer1   | 2012-01-03 | good bye world       |
6  | 3362 | sample2  | customer1   | 2012-01-04 | good bye world       |
7  | 3362 | sample2  | customer1   | 2012-01-05 | good bye new world   |

当我分组时

1  | 1342 | sample1  | customer1   | 2012-01-01 | hello world          |
4  | 3362 | sample2  | customer1   | 2012-01-02 | good bye world       |

但我需要

3  | 1342 | sample1  | customer1   | 2012-01-03 | hello new world      |
7  | 3362 | sample2  | customer1   | 2012-01-05 | good bye new world   |

这就像用最大ID或最大创建时间的TN分组。
我该怎么做？谢谢！

最佳答案

SELECT t2.* FROM
(SELECT MAX(id) AS id,tn FROM my_table GROUP BY tn) AS t1
LEFT JOIN my_table AS t2 USING(id)